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MBB Background check

Hello,

I recently landed an offer from one of the MBB in the US, and am running into a very stressful issue regarding background check.

I did a informal cash-based side hustle business in college for 2 years, in which I listed on my resume to showcase business skill and background, and was told by the background check company specifically to leave it off the background check form because they will not be able to verify it. Now, the employer flagged it and want additional proof. And unfortunately, I lost all records of the side hustle about a year ago when my old laptop suffered a Trojan virus attack and wiped essentially all of my records clean. With that said, I physically am not able to prove that I actually worked on this side hustle in any sort of way.


Will this be a major issue that could get my offer revoked, given that my previous main W-2 employment and education records have been properly verified?

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Profile picture of Carlos
Carlos
Coach
on Sep 29, 2026
Free 15 min intro | Engagement manager | 5+ yrs interviewing candidates | 90%+ success rate

Hi there,

I would not assume this is an offer ending issue. The key distinction here is between something being difficult to verify and the firm finding inconsistencies in how you described it.

A few things are in your favour:

• This was an informal side business during college, not one of your main employers.

• Your main W2 employment and education have already been verified.

• Most importantly, the background check provider specifically told you not to include the side hustle because they would not be able to verify it through their standard process.

At this point, I would focus on giving the firm a clear, consistent and credible explanation. Make sure the dates, scope and way you describe the business are exactly consistent with what you originally put on your resume and discussed during recruiting.

I would also look for any legitimate indirect evidence that may still exist, such as old bank transactions, emails, messages, customers, marketplace profiles or someone who could confirm the activity. But if nothing exists, do not try to manufacture evidence just to close the gap.

I would also avoid making the Trojan issue the centre of the explanation. The core story is simply that the activity was genuine, the provider told you not to list it because it could not be formally verified, and you no longer have the original records.

So yes, there is something that needs to be resolved, but a request for additional proof does not automatically mean the firm believes you were dishonest. Your priority now should be consistency, transparency and credibility.

Best,
Carlos

Profile picture of Margot
Margot
Coach
on Sep 29, 2026
Senior Strategy Consultant & interviewer | Proprietary cases in EN, DE, FR, IT | ex Accenture, BCG, Deloitte

Hi there,

In the processes I have seen, a request for additional proof is what happens when an entry cannot be closed, not what happens when an entry is disbelieved. Which of those you are in is still being decided by how you respond, not by the records the virus took.

The distinction that matters here is unverifiable versus inconsistent. An entry nobody can confirm is a common and survivable outcome. An entry described one way on a resume and a different way under questioning is the one that damages an offer, because it stops being about the side hustle and starts being about your account of it.

A few things I would do before replying:

  • Assemble the indirect evidence first, then respond once. Bank deposits from those two years if the account still exists, any tax filing that touched the income, an archived marketplace profile or website, old messages with customers.
  • Ask two or three people who bought from you for a short written statement with dates and what they saw. Named individuals attesting in writing beat your current position, which is nothing.
  • Put the vendor's instruction in writing, with the date and the person who gave it. The reason your form and your resume differ is that you were told to leave it off, and that belongs on the record rather than in your memory.
  • Describe it now exactly as you described it then. If the resume called it a business, I would not quietly downgrade it to a hobby under pressure.
Profile picture of Ian
Ian
Coach
on Sep 29, 2026
Ex-BCG | NYU Stern | MBB, Tech, & Strategy Coach | 5,000+ Sessions | 500+ Offers | 1,000+ Candidates | 100+ Countries

First, don't panic. But because they've specifically flagged it, you do need to deal with this properly.

Background checks are basically there to answer one question:

Did you tell the truth?

I would be completely transparent with HR / the background check team:

  1. It was a genuine informal side hustle
  2. It was cash-based
  3. The background-check provider specifically told you not to list it on their form because they couldn't verify it
  4. Your records were subsequently lost
  5. You're happy to provide anything else they consider acceptable

Before deciding you have literally no proof, think broadly. Is there really nothing anywhere?

  • Former clients who can confirm the work
  • Emails still sitting in Gmail / Outlook
  • Messages or WhatsApp conversations
  • Bank deposits
  • Tax filings, if applicable
  • Old website / social media pages
  • Calendar entries
  • Cloud storage
  • Photos
  • Someone who worked with you or knew about the business

You don't necessarily need the perfect formal employment record. Ask them what alternative corroboration they will accept.

Could an unverifiable experience theoretically become a problem? Yes. I wouldn't tell you there's zero risk.

But don't jump from “they've asked for evidence” to “my offer is getting revoked.”

Your main employment and education checking out obviously helps. Now just be transparent, don't invent evidence, and work with HR on what they will accept.

Profile picture of Cristian
on Sep 29, 2026
ex-McKinsey | Holistic approach | >400 clients coached

Hi there, 

I'm sorry to hear this. 

I doubt this would lead to your offer being revoked. As long as you're able to explain what happened, I would imagine they would be reasonable about it. These things do happen. 

Congrats on the offer and I hope it all goes smoothly ahead!
Best,
Cristian

Profile picture of Alessa
Alessa
Coach
6 days ago
Ex-McKinsey | Ex-BCG | Ex-Roland Berger

Hey!!

I wouldn’t panic yet. The fact that your main employment and education have been verified is important, and the fact that the background check company specifically told you not to include the side hustle is also relevant.

I’d be completely transparent with the recruiter and explain exactly what happened, including that you listed the experience on your CV but were advised to leave it off the verification form because it couldn’t be independently verified. Ask what alternative evidence they would accept. Even if you no longer have the original records, things like old emails, bank statements, invoices, messages or tax records could potentially help if you have access to any of them.

I wouldn’t try to create or reconstruct evidence. Just explain the situation clearly and let the firm decide how they want to handle it.

Best, Alessa :)

Profile picture of Ashwin
Ashwin
Coach
3 days ago
Ex-Bain | Help 500+ aspirants secure MBB offers

This can become a problem, and it is not automatically the end of the offer. Verified employment and your degree are the core of a US check. The risk is the CV line you cannot evidence, after the screening firm told you to leave it off and the employer still asked.

Write to the recruiter before they chase you again. State what the work was, the years, that it was informal and paid in cash, and that the records went with the laptop. Say plainly that you cannot produce invoices. Offer whatever still exists: a client or a classmate who will confirm the work, a tax filing, a bank deposit, or a short description of what you sold and to whom. Ask how they want that line treated. Do not drop it from the story you already told if the CV they assessed included it. Do not rebuild a spreadsheet and present it as an original record.

I can't tell you the offer will survive. Firms treat an unverifiable claim more harshly when it looks inflated than when you flag the limit yourself. A clear note now keeps the decision with them, on the facts you still have.

Profile picture of Vanessa
Vanessa
Coach
on Sep 29, 2026
Former McKinsey Senior Recruiter & Zeiss CVC | Insights from the Other Side of the Table | CV & Personal Fit Mastery

Congrats on your offer! To be honest: it sounds a bit confusing. Are you sure there is no proof you can show anymore (a tiny one?)? The most important thing for that situation is trust, that you are honest about it. So make sure they can believe you.